Diffusion kurtosis imaging for differentiating between the benign and malignant sinonasal lesions.

PURPOSE: The study aimed to evaluate diffusion kurtosis imaging (DKI) in the differentiation between benign and malignant sinonasal lesions, and to compare the diagnostic performance of DKI with diffusion weighted imaging (DWI). MATERIALS AND METHODS: Eight-one patients with solid sinonasal lesions confirmed by surgery and pathology (46 malignant and 35 benign) underwent conventional MRI, DWI, and DKI. DKI was performed employing a 13 extended b-value ranging from 0 to 2500 s/mm2 . Apparent diffusion coefficient (ADC) from DWI, kurtosis (K), and diffusion coefficient (D) from DKI were measured and compared between two groups. RESULTS: ADC and D values were significantly lower in the malignant sinonasal lesions than in the benign sinonasal lesions (1.11 ± 0.41 versus 1.58 ± 0.50 × 10-3 mm2 /s and 1.45 ± 0.36 versus 2.03 ± 0.49 × 10-3 mm2 /s, respectively, both P < 0001). K value was significantly higher in the malignant lesions than in the benign lesions (0.91 ± 0.23 versus 0.57 ± 0.24, P < 0001). The receiver operating characteristic curve analyses yielded a cutoff ADC value of 1.27 × 10-3 mm2 /s for differentiating between benign and malignant lesions, with a sensitivity of 69.6%, a specificity of 77.1% and an accuracy of 74.0%; a cutoff D value of 1.75 × 10-3 mm2 /s, with a sensitivity of 82.6%, a specificity of 77.1% and an accuracy of 80.2%; a cutoff K value of 0.63 with a sensitivity of 95.7%, a specificity of 77.1% and an accuracy of 87.7%. The area under the curve of K value was significantly larger than that of ADC value (0.875 versus 0.762; P < 0.05). CONCLUSION: K value of DKI demonstrates significantly higher accuracy compared with ADC value for the differentiation between benign and malignant sinonasal lesions. DKI may be a noninvasive method to evaluate the sinonasal lesions. LEVEL OF EVIDENCE: 1 J. MAGN. RESON. IMAGING 2017;45:1446-1454.

Case report: Rare benign obstructive disease of the biliary tract-a rare case of eosinophilic cholangitis.

Objective: Eosinophilic cholangitis (EC) is an uncommon form of benign biliary obstruction. It frequently eludes accurate clinical diagnosis, leading to inappropriate treatment methods. It is our aspiration that this clinical report will impart comprehensive insights into EC and, specifically, the critical role of tomographic examination. Case summary: A 34-year-old man was urgently admitted to the hospital due to excruciating abdominal distress persisting for several hours. Following a six-day course of anti-inflammatory therapy, his symptoms displayed marginal improvement, prompting his discharge. He returned to the hospital a month later for re-examination on doctor's orders. Based on the results of the re-examination, the patient refused steroid hormone shock therapy and subsequently underwent laparoscopic left-lateral hepatic lobectomy in order to confirm the diagnosis. The preoperative absolute counts of eosinophils in the peripheral blood were documented as 2.3 × 109/L, 3.06 × 109/L, and 1.50 × 109/L consecutively; concurrently, the corresponding percentages of eosinophils were quantified at levels of 21.90%, 30.70%, and 19.20%. The subsequent postoperative pathological assessment unveiled EC as the definitive diagnosis. The patient has since remained free from disease recurrence and is presently alive. Conclusion: When encountering a patient presenting with persistent elevation in absolute eosinophil count in peripheral blood, coupled with imaging manifestations suggestive of intrahepatic periductal inflammation, diagnosis of EC should be highly suspected. The most optimal diagnostic and therapeutic workflow for EC could entail CT-guided liver lesion biopsy, ensued by glucocorticoid pulse therapy, and finally, short-term monitoring utilizing CT or MRI (including T1WI, T2WI, DWI, CEMRI) techniques.

Changes in DTI parameters in the optic tracts of macaque monkeys with monocular blindness.

For humans and non-human primates, the alteration of the visual pathway's white matter fibers after visual deprivation has been partially explored. However, the changes in the optic tracts after the transection of the optic nerve have not been well characterized. In the current study, we attempted to investigate the differences in optic tracts between normal and unilateral optic nerve transected macaque monkeys using diffusion tensor imaging (DTI). Four healthy neonatal macaque monkeys were randomly divided into 2 groups, with 2 in each group. Group A served as a control group, and Group B underwent unilateral (right eye) optic nerve transection to produce monocular blindness. Sixteen months (Group B16M) and thirty-two months (Group B32M) after optic nerve transection, diffusion tensor imaging was performed on all monkeys. Then, we compared fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity (RD) in bilateral optic tracts between Group A and Group B and between Group B16M and Group B32M. In both Group B16M and Group B32M, when compared with normal monkeys in Group A, FA was decreased and MD, AD and RD were increased in the bilateral optic tracts of monkeys with monocular blindness. Furthermore, compared with Group B16M, FA was reduced and MD, AD, RD were more obviously increased in the bilateral optic tracts of Group B32M, and noticeable differences in MD, AD and RD were found between the left and right optic tracts in group B32M. We believe that the results of this study would be helpful in investigation of the histological abnormalities of the integrity damage, axonal degeneration and demyelination of optic tracts in macaque monkeys with monocular blindness by DTI parameters in noninvasively and quantitatively.